Change-over mechanism for moving picture projectors



Dec. 6 c. J. GOODMAN ET AL CHANGE-OVER MECHANISM FOR MOVING-PICTURE PROJECTORS Filed April 1, 1948 $4) rii's J Goodman Aubrey L. Wesf INVENTORS.

9 BY (Wavy 3M Patented Dec. 6, 1 949 1 CHANGE-OVER MECHANISM FOR MOVING PICTURE PROJECTORS Curtis J. Goodman and Aubrey L. West, Lafayette, Tenn.

Application April 1, 1948, Serial No. 18,396

1 Claim. (Cl. 88-16) Our invention relates to improvements in change-over mechanisms for moving picture projectors, the primary object in view being to provide a simply constructed mechanical changeover for selectingly cutting out either of a pair of such projectors, as occasion may require, quickly and easily, by foot pressure.

Another object is to provide mechanism of the character and for the purpose above set forth which is adapted for quick easy installation without altering the projectors and which is not liable to get out of order nor require frequent servicing.

Other and subordinate objects, also within the purview of our invention, together with the precise nature of our improvements will be readily understood when the succeeding description and claims are read with reference to the drawing accompanying and forming part of this specification.

In said drawing:

Figure 1 is a view in front elevation of our improved change-over mechanism, in a preferred embodiment thereof, applied to a pair of moving picture projectors, shown partly in broken lines;

Figure 2 is an inverted perspective view of the actuator drawn to a larger scale;

Figure 3 is a view in longitudinal section of a portion of the actuator taken on a line 33 of Figure 2, and drawn to a larger scale;

Figure 4 is a detailed view in transverse section taken on the line 4-4 of Figure 3;

Figure 5 is a view in perspective of one of the pedals.

Referring to the drawing by numerals, according to our invention, a pair of side-by-side, moving picture projectors, designated I, 2 and shown diagrammatically in broken and full lines, as sufficient for the present purposes, are equipped with guides 3, 4 at the apertures 5, 6 thereof and for vertically slidable change-over shutters 1, 8.

Mechanical means are provided for operating the shutters I, 8, alternately, to cut out either projector I, 2, and comprising the following.

A pair of foot pedals 9, ID are provided alongside the outboard sides of the projectors I, 2, respectively, which are hinged as at II, I2 to attaching plates, as at I3, secured by screws I4 to the floor I5 of the projection room, not shown, so that said pedals are vertically swingable. Stop screws, as at I6, in said pedals 9, III are adjustable for engagement with the floor I5 to limit downward swinging of the pedals 9, In as may be required.

The pedals 9, I0 are operatively connected to the shutters I, 8 by means now to be described.

A pair of pull cables I1, I 8 are extended upwardly from the pedals 9, l0 over a pair of pulleys I9, 20 suitably fixed to the ceiling 2I of the projection room for connection to an actuator 22 for operating a pair of shutter raising and lowering Bowdin wires 23, 24. The pull cables II, I8 are connected at lower ends thereof by clamps 25, 26 to short length cables 21, 28 attached, in any suitable manner, to the pedals 9, Ill.

The actuator 22 comprising a bar-like bracket 29 secured by screws 30 to the ceiling 2I midway between the projectors I, 2 and having a pair of depending end bearing ears 3|, and a lateral arm 32 projecting downwardly from the center of said bracket, as best shown in Figure 2 and secured to said bracket, as at 33. A horizontal lever 34 is pivoted adjacent one end thereof, as at 35, on said arm 32 to swing from side to side with a pair of upstanding posts 36, 31 on one end thereof to which the upper ends of the pull cables I'I, I8 are suitably connected. A shouldered bolt 38 extends upwardly in a longitudinal slot 39 in the other end of the lever 34 to slide along said slot, for a purpose presently clear, and, by means of a nut 40, is fixed in a two-part plate clamp 4I, intermediate the ears 3|, and secures the parts of said clamp in clamping relation. The clamp 4| at one end thereof is clamped to a slide rod 42 slidably extended at its ends through the ears 3| transversely of the projectors I, 2, and is adapted to be moved from side to side with the slide rod 42 sliding endwise to exert pull on the Bowdin wires 23, 24 alternately.

The Bowdin wires 23, 24 are suitably connected at lower ends thereof to the shutters I, 8 to raise and lower the same with lower ends of the sheaths 42, 43 for said wires fixed by clamps 44, 45 to the projectors I, 2 above the shutters I, 8 and said wires and sheaths extend upwardly to opposite ends of the bracket 23 of the actuator 22. The upper ends of the sheaths 42, 43 are fixed by snap rings as at 46, in tubular couplings 41, 48 extending oppositely, outwardly, from the ears 3| and threaded into nuts 49, 50 fixed to said ears by welding, not shown. The upper ends of the Bowdin wires 23, 24 extend through said couplings 41, 48 and through openings, as at 49, in said ears and are clampingly engaged in end to end relation by the end of the clamp 4I opposite that clamped to the slide rod 42.

In operating the described change-over mechanism, depression of either pedal 9, III, will,

through corresponding pull cables I1, I 8 swing the lever 34 to one or the other side of a central position, for instance, as shown in Figure 1, with pedal l0 depressed. Such swinging of said lever 34 will cause the clamp 40 to move in a corresponding direction to exert a pull on one Bowdin wire, for instance, wire 23, and a push on the other Bowdin wire, for instance, 24, to close the shutter of the projector adjacent the depressed pedal and raise the shutter of the remote projector, thus cutting 011 the adjacent projector and changing over to the remote one. pressed, the other is raised for operation. be seen, the pull cables 11, I8 and the Bowdin wires may be cut to difi'erent lengths as may berequired by different spacings of the projectors l, 2 in a projector room and different heights of ceilings of such rooms.

The foregoing will, it is believed, sufiice to impart a clear understanding of our invention, with- :2

side projectors each having an aperture and a 30 2,448,220

When one pedal 9, or H], is de- As will 4 shutter operative to open said aperture, said mechanism comprising an over-head shutter actuator including a fixed bracket, a lever pivotally mounted intermediate its ends on said bracket for swinging in opposite directions, a clamp, a slide rod on said bracket to which said clamp is fixed for movement in opposite directions by sliding of said rod, and sliding pivotal connections between said clamp and one end of said lever whereby movement of the lever in opposite directions correspondingly moves said clamp, a pair of flexible wires with ends gripped by said clamp and ends, connected to said shutters and whereby -movement of said clamp in opposite directions operates said shutters to open said apertures alternately, and a pair of pedal operated pull wires connected to the other end of said lever for swinging the same in opposite directions.

CURTIS J. GOODMAN. AUBREY L. WEST.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 2,054,268 Owens Sept. 15, 1936 2,988,574 Brown ,v Aug. 3, 1937 Jenkins, Aug. 31, 1948 

